Within the last 19 months, since we have been participating in the subtreatment group of the National Prostatic Cancer Project, we have entered a total of 61 patients. Presently we have 42 active patients on different protocols. In our group of 61 patients we have had one complete response, eight partial responses and 20 in the stable category. Concomitant evaluation of the immunological studies of these patients in our institution indicate a definite relationship of their response to therapy with improvement of natural killer activity in cytotoxicity assays. We believe that a significant number of patients have benefited from this program.